{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/104506"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/104506","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"A protection scheme for alternator fields","abstract":"A synchro-generator and a unijunction transistor oscillator in conjunction with a silicon-controlled rectifier form a detection and relay circuit for voltages appearing across the field of a three-phase alternator generated by negative-phase-sequence currents due to unbalanced conditions. Readings were taken of the times required for operation of the relay for various conditions of unbalance. Statistical studies were made to enable time predictions to be offered. It was concluded that the scheme offers the possibility of faster operation, and hence better protection and system stability, than is possible with existing types. In addition, the scheme will result in no loss of dependability over existing types, and the relay portion offers outstanding ruggedness and sensitivity.","abstract_html":"A synchro-generator and a unijunction transistor oscillator in conjunction with a silicon-controlled rectifier form a detection and relay circuit for voltages appearing across the field of a three-phase alternator generated by negative-phase-sequence currents due to unbalanced conditions. Readings were taken of the times required for operation of the relay for various conditions of unbalance. Statistical studies were made to enable time predictions to be offered. It was concluded that the scheme offers the possibility of faster operation, and hence better protection and system stability, than is possible with existing types. In addition, the scheme will result in no loss of dependability over existing types, and the relay portion offers outstanding ruggedness and sensitivity.","abstract_has_math":false,"creators":["Lancaster, James Terry"],"institution":"Virginia Polytechnic Institute","degree_name":"M.S.","degree_level":"masters","degree_discipline":"Electrical Engineering","degree_department":"Electrical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1965,"date_issued":"1965","date_published":"1965","updated_at":"2026-07-22T22:18:55Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/104506","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Electrical Engineering"]},{"key":"dc:creator","label":"Author","values":["Lancaster, James Terry"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-08-02T18:38:55Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-08-02T18:38:55Z"]},{"key":"dc:date.issued","label":"Date","values":["1965"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/104506"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A synchro-generator and a unijunction transistor oscillator in conjunction with a silicon-controlled rectifier form a detection and relay circuit for voltages appearing across the field of a three-phase alternator generated by negative-phase-sequence currents due to unbalanced conditions. Readings were taken of the times required for operation of the relay for various conditions of unbalance. Statistical studies were made to enable time predictions to be offered. It was concluded that the scheme offers the possibility of faster operation, and hence better protection and system stability, than is possible with existing types. In addition, the scheme will result in no loss of dependability over existing types, and the relay portion offers outstanding ruggedness and sensitivity."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["M.S."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A protection scheme for alternator fields"]}]}],"canonical_facts":{"dc:contributor.department":["Electrical Engineering"],"dc:creator":["Lancaster, James Terry"],"dc:date.accessioned":["2021-08-02T18:38:55Z"],"dc:date.available":["2021-08-02T18:38:55Z"],"dc:date.issued":["1965"],"dc:description.abstract":["A synchro-generator and a unijunction transistor oscillator in conjunction with a silicon-controlled rectifier form a detection and relay circuit for voltages appearing across the field of a three-phase alternator generated by negative-phase-sequence currents due to unbalanced conditions. Readings were taken of the times required for operation of the relay for various conditions of unbalance. Statistical studies were made to enable time predictions to be offered. It was concluded that the scheme offers the possibility of faster operation, and hence better protection and system stability, than is possible with existing types. In addition, the scheme will result in no loss of dependability over existing types, and the relay portion offers outstanding ruggedness and sensitivity."],"dc:description.degree":["M.S."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/104506"],"dc:language.iso":["en"],"dc:publisher":["Virginia Polytechnic Institute"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["A protection scheme for alternator fields"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Electrical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["M.S."],"thesis:institution_name":["Virginia Polytechnic Institute"]},"updated_at":"2026-07-22T22:18:55Z"}